qcacld-3.0: Possible memory leak in set dwell time api

Dynamically allocated memory is not freed in error case
for sme_config in set dwell time api, this may lead to
mem leak in error case.

Free the dynamically alolocated memory in error case.

Change-Id: Id74c28fbe5600495c86d2e0e8cc2b6809f5b3b48
CRs-Fixed: 2466253